/*	
 *  Copyright (c) 2009-@year@. The GUITAR group at the University of Maryland. Names of owners of this group may
 *  be obtained by sending an e-mail to atif@cs.umd.edu
 * 
 *  Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated 
 *  documentation files (the "Software"), to deal in the Software without restriction, including without 
 *  limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
 *	the Software, and to permit persons to whom the Software is furnished to do so, subject to the following 
 *	conditions:
 * 
 *	The above copyright notice and this permission notice shall be included in all copies or substantial 
 *	portions of the Software.
 *
 *	THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT 
 *	LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO 
 *	EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER 
 *	IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR 
 *	THE USE OR OTHER DEALINGS IN THE SOFTWARE. 
 */
package edu.umd.cs.emut.model;

import java.util.List;
import java.util.Map;

import org.apache.commons.lang.builder.HashCodeBuilder;

import edu.umd.cs.emut.model.xml.ObjectFactory;


/**
 * 
 * @author <a href="mailto:baonn@cs.umd.edu"> Bao N. Nguyen </a>
 * 
 */
public class WebDefaultIDGenerator extends EIDGenerator {

	/**
	 * 
	 */

	static WebDefaultIDGenerator instance = null;
	static ObjectFactory factory = new ObjectFactory();
	static final int prime = 31;

	private WebDefaultIDGenerator() {

	}

	public static WebDefaultIDGenerator getInstance() {
		if (instance == null) {
			instance = new WebDefaultIDGenerator();
		}

		return instance;
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @seeedu.cs.umd.emut.model.IIDGenerator#generateID(edu.cs.umd.emut.model.
	 * IComponent)
	 */
	@Override
	public String generateID(EComponent component) {

		Map<String, List<String>> properties = component.getProperties();
		String id = component.getFirstValueByName(WebConstants.WEB_ELEMENT_ID);

		HashCodeBuilder builder = new HashCodeBuilder();

		// use the existing id if there is any
		if (id != null) {
			builder.append(id);
			// otherwise consider ID properties
		} else {

			for (String name : ID_PROPERTIES) {
				List<String> valueList = properties.get(name);
				if (valueList != null) {
					builder.append(name);
					for (String value : valueList) {
						builder.append(value);
					}
				}
			}
		}
		String ID = Integer.toString(Math.abs(builder.toHashCode()));
		return ID;
	}

	static String[] ID_PROPERTIES = { "tag", "name", "href" };
}
